The present invention relates generally to the field of material handling; more particularly, to systems and methods of material handling using autonomous mobile drive units and movable inventory trays.
The order fulfillment step in the distribution system process is often one of the largest cost components in moving inventory from production to end consumer. This is due to the fact that final order assembly is typically labor intensive and time consuming as operators move among inventory locations and manually handle items. The order fulfillment step involves selecting multiple individual inventory items from among a large assortment of possible items. In contrast, the steps prior to the order fulfillment step in the distribution system process are generally more efficient since they handle inventory in bulk operations such as moving a truckload at a time, a full pallet of one product, or even whole cases.
Due to its large labor costs, order fulfillment operations have long been the focus of innovations designed to reduce labor. These developments have taken the form of pick-to-light technology, wireless barcode readers, conveyor systems that move orders to operators and even automated storage and retrieval systems (xe2x80x9cASRSxe2x80x9d) that bring the inventory to the worker. Common ASRS solutions are sometimes called carousels or stockers. A typical carousel may have several thousand storage bins installed in a rotating structure that operates similar to the spinning clothes rack at a dry cleaning facility. Another type of solution known as a sorter is used in conjunction with inventory storage equipment and comprises a revolving tray mechanism that helps sort items coming from inventory into their target order bins. Yet another solution is to provide fixed racking aisles served by a gantry robot that moves in and out of the aisles to bring inventory to the front of the storage system.
These solutions have been embraced by the distribution industry for their ability to streamline operations and cut operating costs. Yet even with these often expensive systems, fulfillment costs remain high and distribution system managers continue to search for ways to reduce operating costs.
Another major shortcoming of the current set of order fulfillment solutions is complexity. These automated systems often involve complex control software, lengthy installation, integration and bring-up time, and fail to perform robustly over long periods. Current solutions must be monitored, tuned, and managed by experts with sophisticated knowledge of the system""s workings. In addition, these systems are often inflexible to new processes that may be required as an organization""s needs change.
What is needed is an order fulfillment system that is simple to install, operate, and maintain, and that would further reduce operating costs.